Field
The present disclosure relates generally to interconnect systems, and more particularly, to a high-speed serial interconnect system.
Background
Electronic devices are typically made up of multiple systems built on integrated circuits (ICs), e.g., silicon chips. The different IC systems can be specialized to handle different functions of the electronic device. For example, a mobile communications device can include an IC system for processing radio frequency (RF) signals received and transmitted through various antennas. The RF antennas in a cell phone, for example, can include antennas to receive and transmit cell communication signals, to receive global positioning system (GPS) signals, etc. The task of processing RF signals received and transmitted by the cell phone can be performed by a radio frequency integrated circuit (RFIC), which may include, for example, power amplifiers (PA), low-noise amplifiers (LNAs), antenna tuners, filters, sensors, power management devices, switches, etc. On the other hand a different IC system, typically called a baseband modem or baseband IC (BBIC), can handle the task of sorting out the various incoming and outgoing RF communications and sending each one to the proper destination (e.g., an incoming GPS signal might be sent to a GPS IC, an incoming cell communication might be parsed into data and voice and sent to the appropriate data processing IC and voice processing IC).
The different IC systems communicate with each other via signal lines. For example, some IC systems can be built as separate IC chips, which can be connected together by soldering them to the same printed circuit board (PCB). In this case, the printed wires on the PCB can serve as the signal lines between the different IC systems on separate chips. In another example, multiple systems can be built on a single IC, which can be referred to as a system-on-a-chip (SoC). In this case, conductive pathways built into the IC chip can serve as the signal lines.
Communication between system ICs is performed using a communication interface, which defines how data is sent and received via the signal lines. In many applications, serial interfaces have become the preferred method for digital communication between IC systems. Serial communication is the process of sending data one bit at a time, sequentially, over a communication channel, such as signal lines. This is in contrast to parallel communication, where several bits are sent as a whole, on a link with several parallel channels. An interconnect or link is a point-to-point communication channel between two ports allowing both of them to send and receive data and messages. Serial interconnects are becoming more common at shorter distances, as improved signal integrity and transmission speeds in newer serial technologies have begun to outweigh the parallel bus's advantage of simplicity (e.g., no need for serializer and deserializer, or SERDES) and to outstrip its disadvantages (e.g., clock skew, interconnect density).
As the speed of data communication increases, so does the power needed to communicate over serial interconnects. In battery-operated devices, such as mobile devices, low power operation is critical to allow longer operation between charges. However, as the need for faster and faster data communication speeds has grown, it has become challenging for serial interconnects to provide the accuracy (e.g., low error rate) required for high-speed communication while operating at a low power.